Process for converting cyannaphthalene sulphonic acids



Patented July 10, 1,928.

UNITEDSTATES; PATENT OFFICE,

RICHARD HEBZ ND. FRITZ SCHULTE, OF FRANKFORT-ON-THE-MAIN, AND WERNER ZEBWECK, OF F ECHENHEIM, NEAR FRANKFORT-ON-THE-MAIN, GERMANY, AS- BIGNOBS '10 GRASSELLI DYESTUFF CORPORATION, OF NEW YORK, N. Y., A COR- PORATION OF DELAWARE.

PROCESS FOR CONViER'IIN G CY ANN APHTHALEN E SULPHONIC ACIDS.

Io Drawing. Application filed February 24, 1927, Serial No. 170,732, and inGermany Kay 17, 1926.

The presentinvention relates to an improved process for converting cyannaphtlia- 'lene sulphonic acids, and to new reaction products produced thereby.

lVe have found, that if cyannaphthalenesulphonic-acids, containing at least one sulphonic group in ortho or para position to the cyanic group, are treatedwith an alkaline acting agent at elevated temperatures, this sulphonic group, standing in ortho or para position to the cyanic group, is easily exchanged for other monovalent radicles.

The products of conversion, thus obtained correspond to the general formula:

ployed cyannaphthalene-sulphonic-acids re mains unattacked and hydroxy-cyannaphthalene-compounds are formed corresponding to the above formula, Y being hydrogen and Z being CN, by acting with stronger alkaline acting agents the cyan groups is saponified to the carboxyamid (Z=CONH inthis case) or to the carboxy group (Z=COOH in this case) where as the sulphonic group is exchanged by. hydroxyl- (OH) when the applied alkaline acting agent is an aqueous caustic alkali, or by an alkoxy group, generally when applying caustic alkalies in presence of an alcohol. This latter reaction, by which an alkoxy group is introduced in the molecule, is a particularly remarkable one without anyanal In this ogy in the naphthalene series. manner especially alkoxy-naphthalene-carboxyamids corresponding to the "above formula. Z bein CONH and Y being an alkyl-residue, awand alkoxynathphoicacids are. 'nedcorresponding to the above formula, Z being COOH and Y being hydrogen or an alkyl residue.

Under the term alkaline acting agents We understand caustic alkalies in presence of water or of an alcohol, acting either at ordinary pressure or in a closed vessel at. elevated pressure. Under milder acting alkaline agents the following have been found especially suitable: basic alkaline salts such as sodium formate, acetate, borate, phosphate; Such agents, the caustic alkalies as Well asthe milder acting agents, may be used advantageously in the presence of inorganic or organic diluents in order to keep the mass homogeneous and easily liquid, such as parafiine, naphthalene, tertiary aromatic bases as dimethylaniline or 'N -alkylcarbazol, higher fatty acids, glycerine or'low melting salts.

The aforesaid reactions take place at remarkably low temperatures, namely at about 250 (1., whereas Boyle and Shedlerand tution products, particularlythose contain ing a halogen or afurther sulphonic-group 1n the nucleus, are obtained by cliazotising the corresponding aminonaphthalene-sulphonlc acids and treating thediazo compounds, thus obtained, with cuprous cyanide, according to Sandmeyers reaction. I

All products of conversion, derived there from, are important intermediates for the production of dyestufl's and pharmaceutical products.

In order to further illustrateour inven- 1 tion the following examples are given.

7 Example 1.

naphthalene -1- sulphonic acid (obtainable "20 parts of the sodium salt of 2-cyan- *mixed with about 40 parts of finely powdered caustic potash and about 150 parts of paraffine and the mixture is heated to about C. while stirring. After some time the mass lowing formula Instead of caustic potash also sodium acetate or formate with or without addition of parafline or another suitable diluent may be used for the reaction. Also heating of the sodium salt of the cyannaphthalene-sulphonic acid by itself eventually with addition of sand or similar acting substances is suflicient for forming the cyannaphthol. This compound is converted into the corresponding 1-naphthol-2-carboxylic acid by treating it with alkaline saponifying agents, f. i. by heating it with dilute caustic alkalies. If the sodium salt of the 1-cyannapl1thalene-4- sulphonic acid is treated in the same manner with a milder acting alkaline agent the corresponding 4-hydroxy-l-cyannaphthalenecompound is obtained.

Ewample 2.

' while stirring to about 200220 C., and the mass is kept at this temperature until the evolution of ammonia ceases, After cooling down, the mass is dissolved in water and, filtered and upon acidifying, the 1.2-hydroxynaphthoic acid of the formula:

g rl'pducts of conversion may be obtained.

us, forinStanee, by treating 2-cyannaphthalene-3.6-disulphomc acid with caustic alkalies according to the conditions applied in this example a new acid is obtained, being probably 3-hydroxy-6-sulphonaphthalene-2- carboxylic acid; by carrying out the process under more vigorous conditions, particularly at more elevated temperatures, there is formed as end product of the reaction 3.6- dihydroxynaphthaIene-Q-carboxylic acid.

Ewample 3.

10 parts of caustic potash and 1 part of water are heated in a suitable vessel until the mass is dissolved. Then 2 parts of the sodium salt of l-cyannaphthalene--sulphonic acid are added at about 160 C. The vessel is closed and then heating is continued under OOH separates as colorless needles. This acid shows all the characteristic ro erties, and the melting point 184l85 (5 escribed by Heller (Ber. d. Deutsch. Chem. Ges. vol. 45,

1-cyannaphthalene-4-sulphonic acid may first be converted into the corresponding 4- sulpho-l-naphthoic acid for instance by heating it with a'caustic potash solution of about 10% strength for some hours under reflux. It may be separated by acidifying and salting'out the mass. By treating this acid with a caustic alkali in the same manner as described above at about 200 (1., the lA-hydroxynaphthoic acid is formed, with an excellent yield, in a pure state.

When subjecting in the same manner the nuclear substitution products of 1.4-cyannaphthalene sulphonic acid such as the 6- and 7-sulpho derivatives, (obtainable by treating diazotised l-naphthylamine-fiand 4.7-

disulphonic ,acids (Dahls acids II and III) with cuprous cyanide according to Sand meyers reaction) to the action of alkaline agents, the corresponding derivatives of the products of conversion may be obtained.

Example 4.

40 parts of caustic potash and 40 parts of methylic alcohol are heated for some time at about 110 C. At this temperature 15 parts of the sodium salt of l-cyannaphthalene-Q- sulphonic acid (obtained from the 1-amino-2- naphthalene-sulphonic acid; see Licbigs Annalen vol. 388, page 7 are added while stirring. The temperature of the mass is slowly increased to about 130440 0. and the mass is kept at this temperature for a short time, until a test portion, when acidified, shows that the formation of a compound, insol-j uble in cold water and in dilute solutions of .alkali carbonates. but soluble in ether, is

finished. Then the mass is poured onto ice, the precipitate thus formed .is filtered and washed with water. When recrystallized from water or benzene, the Q-methoxy-naplu thalene-l-carboxyamide of the probable formula coma OCH:

Ezomple5.

40 parts of caustic potash and 25 parts of methylic alcohol are heated for some time at about C. At this temperature 10 parts of the sodium'salt of 2-cyannaphthalene-l-sulphonif' acid are added. The temperature of the mass is increased to about C., and the mass is kept for a short time at this temperature, until .a test portion as described in the foregoing example,

shows the formation of a compound insol able in dilute solutions of alkali carbonates. Then the reaction mass is cooled down and diluted with water. Thereby a precipitate,

which is insoluble in alkalies is so arated" 7 p reaction is-mcreased to about 120 C. (by

out. It is filtered and washed witlrwater.

The new compound, being probably 1- methoxvnaphthaIeneQ-carboxy-amide of the formula:

crystallizes from water or dilute alcohol as long colorless needles, 157 C.

By saponifying the'new compound with alkaline acting agents.-for instance, by

heating it with a dilute caustic soda solution,

preferably with addition of alcohol, until the evolution of ammonia ceases,it is converted into the corresponding l-methoxy naphthalene-Q-carboxylic-acid, which forms,

melting at .when recrystallized from. dilute alcohol,

bright needles, melting atv 127 0., as describedin the literature (see Hiibner. Monatshefte fiir Chemie, vol. 15, page 735).

' henusing other aliphatic alcohols for the process the corresponding alkoxy derivatives are formed. The same reaction takes "place when using benzyl alcohol or also aromatic phenol. htlrpolyvalent alcohols such as glycol the corresponding derivatives are formed.

E wample 6'.

1 part of the sodium salt oil-cyanhaphthalene-el-sulphonic acid is added at about 95 C., to a mixture 0P4 parts of caustic potash and 6 parts of methylic-alcohol. Then the mixture is heated under reflux for some hours until a test portion as described in example l shows that the formation of a compound, insoluble in dilute solutions of alkali carbonates, is finished. zAfter-cooling down, the mass is diluted with water and the separated 4-methoxy-l-naphthaniide of the formula: 5

OCH:

is isolated by filtration. It has the properties described in the literature (cf. (J'rattermann, Liebigs Annalen, vol. 2&4, page 73, who prepared it in a complicated manner. unfit for technical purposes byreacting with urea-chloride and aluminiuni-chloride on anaphtholether). I

When recrystallized from dilute alcohol it is obtained as colorless crystals, melting at 237 C. It is insoluble in cold alkalies;

when heated with caustic alkaline solutions it isjconverted into the corresponding carboxylic acid.

When, in this process, the temperature of partly distilling oil the alcohol,) evolution for some honrs at this temperature, until a test portion, when acidified, shows that the formation of a compound, easily soluble in dilute solu'tions of alkali carbonates. is finished, the formed l-methoxy l-naththoicacid of the formula:

(,OOH

. OCH; I may be separated out by diluting the mass with water and acidifying it The said recrystallized from dilute alcohol (cf. Gattermann, l. c.).

It may also be obtained by subjecting the above memtioned 1-cyannaphthalene-4-sulphonic acid (see exampde 3) to the process described in the present example.

Example 7.

If, insteadof methylic-alcohol, ethylic-alcohol, is used and the process is otherwise carried out as described in the foregoing example, i-ethoxy-l-naphthamide and 4- ethoxy-l-naphthoic-acid are obtained, hav- 7 m the properties described in the literature (c Gattermann, c.). The t-ethoxy-lnaphthamide crystallizes from dilute alcohol as colorless needles, melting at 241 C. It is insoluble in cold alkalies; when heated with a caustic alkaline solution the corresponding acid is formed. This 4-ethoxy-1- naphtholc-acid crystallizes from dilute alcohol as colorless needles, melting at 214 C. It is easily soluble in alkalies.

Example 8.

When using n-butylic alcohol instead of methylic alcohol and carrying out the reaction otherwise as described in the fore oing examples, at first" l-n-butyloxy-l-nap thamide of the formula:

cone

CHaCHgCHzCH: is obtained. The new compound crystallizes from spirit in silver slunlng needles, melting at 250 C By increasing the temperature of the re- 1 action, the corresponding 4-n-butyloxy-lnaphthoic acid of the formula:

OCHaCHaCHaCH:

is obtained, being also a new compound, crystallizing from splrlt as colorless needles and melting at 208 C.

In an analogous manner alkyloxy-compounds of higher fatty alcohols may be produced.

Among the products of converslon, derived from orthoand para-cyannaphthalene solphonic acids, herein described, the hydroxynaphthoic-acids obtainable according to the aforesaid reaction with an excellent yield and in a pure state are already known in the literature, whereas the hydroxycannaphthalene-compounds, obtainable as mtermediates bythis reaction, are new bodles.

The alkoxynaphthamides and alkoxy-naphthoic-acids are new compounds with the exception of the following, which have been prepared in a complicated manner, unfit for technical purposes, as stated above:

1) 2 methoxy 1 naphthamide, (Liebigs Annalen, vol. 244, page 75).

5?) 2-ethoxy-l-naphthamide, (l. c., page 7 3) 4-methoxy-l-naphthamide, (l. 0., page 73 4) 4-ethoxy-1-naphthamide, (l. 0., page 3 wherein the Xs represent hydrogen atoms of which one or more may be replaced by a monovalent substituent and wherein the cyanogen and the sulphonic acid groups stand in ortho or para position to each other.

2. The process which comprises treating with an alkaline acting agent at a temperature of from about 80 to about 250 C. a compound of the general formula wherein the Xs represent hydro en atoms of which one or more may be rep aced by a monovalent substituent and wherein the cyanogen and the sulphonic acid groups stand in ortho or para position to each other.

3. The process which comprises treating with an alkaline acting agent at a temperature of from about 80 to about 150 C. a compound of the general formula wherein the Xsrepresent hydrogen atoms of which one or more may be replaced by a mouovalent substituent and wherein the cyanogen and the sulphonic acid grou s stand in ortho or para position to each 0t ier.

4. Process which comprises treating 2- cyannaphthalene-l-sulphonic acid with caustic potash in the presence of parafiine at a temperature of about 140 C.,' and precipitating the reaction product .by acidifying the diluted react-ion mass. I

5. As new products thecompounds of the general formula combining with diazo compounds.

6. As a new product the compound of the probable formula:

forming long needles melting at 179' C. when recrystallized from dilute alcohol, and being capable of combining with diazo compounds.

In testimony whereof, we afiix our signatures.

RICHARD HERZ. FRITZ SCHULTE. \VERNER ZERWECK. 

